The present invention relates to a securing member for wear parts for earth-moving machines. Such "wear parts" primarily are teeth and exchangeable cutting edges for excavator and loader buckets, scarifier teeth, teeth for dredge cutters. A great number of different types of securing members have been proposed and tried out for this purpose during the course of the years, but most of the types have been abandoned as they have not proved to be entirely reliable, have had poor resistance to wear and other stresses, or have been altogether too much trouble to install or remove.
One of the absolutely best design principles, which is used in very many variants, is a locking wedge consisting of two longitudinal edge parts made of metal, which are held together by an elastic middle part of comparatively hard rubber. Locking wedges of this type are pressed into a through opening where the edge parts will be in contact with both the part which is to be held fast and the main component to which this part is to be secured. The through opening is then made so much smaller than the width of the locking wedge that its middle part of rubber must be compressed to a certain degree. This makes the wedge fit without play. Since the edge parts usually are provided with locking edges of various shapes which coact with other locking edges on the parts secured relative to each other by the wedge, the risk that the wedge will work out of the locking opening is practically eliminated. The locking wedge can moreover easily be removed by knocking it out with the aid of a drift and a sledge hammer. A representative locking wedge of this type is described in the Swedish Pat. No. 333.551, which corresponds to U.S. Pat. No. 3,879,867 issued Apr. 29, 1975 for a Fastening Means For Retaining A Digger Tooth In A Socket.
However, locking wedges of the main type outlined above cannot readily be used when it is desired to insert the securing member along the same path as the one in which it is desired to lock the parts against movement. As a rule, this does not pose any problems, as in most cases, without any disadvantages, the through locking opening can be applied across the locking direction, but in certain cases it may be appropriate, in fact even necessary, to apply the securing member from the same direction as the wear part itself is inserted.